texinfo: Object-Oriented Methods

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Object-Oriented Variables

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16.5.6.2 Object-Oriented Methods
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These commands allow you to define different sorts of function-like
entities resembling methods in object-oriented programming languages.
These entities take arguments, as functions do, but are associated with
particular classes of objects.

'@defop CATEGORY CLASS NAME ARGUMENTS...'
     The '@defop' command is the general definition command for these
     method-like entities.

     For example, some systems have constructs called "wrappers" that
     are associated with classes as methods are, but that act more like
     macros than like functions.  You could use '@defop Wrapper' to
     describe one of these.

     Sometimes it is useful to distinguish methods and "operations".
     You can think of an operation as the specification for a method.
     Thus, a window system might specify that all window classes have a
     method named 'expose'; we would say that this window system defines
     an 'expose' operation on windows in general.  Typically, the
     operation has a name and also specifies the pattern of arguments;
     all methods that implement the operation must accept the same
     arguments, since applications that use the operation do so without
     knowing which method will implement it.

     Often it makes more sense to document operations than methods.  For
     example, window application developers need to know about the
     'expose' operation, but need not be concerned with whether a given
     class of windows has its own method to implement this operation.
     To describe this operation, you would write:

          @defop Operation windows expose

     The '@defop' command is written at the beginning of a line and is
     followed on the same line by the overall name of the category of
     operation, the name of the class of the operation, the name of the
     operation, and its arguments, if any.

     The template is:
          @defop CATEGORY CLASS NAME ARGUMENTS...
          BODY-OF-DEFINITION
          @end defop

     '@defop' creates an entry, such as ''expose' on 'windows'', in the
     index of functions.

'@deftypeop CATEGORY CLASS DATA-TYPE NAME ARGUMENTS...'
     The '@deftypeop' command is the definition command for typed
     operations in object-oriented programming.  It is similar to
     '@defop' with the addition of the DATA-TYPE parameter to specify
     the return type of the method.  '@deftypeop' creates an entry in
     the index of functions.

'@defmethod CLASS NAME ARGUMENTS...'
     The '@defmethod' command is the definition command for methods in
     object-oriented programming.  A method is a kind of function that
     implements an operation for a particular class of objects and its
     subclasses.

     '@defmethod' is equivalent to '@defop Method ...'.  The command is
     written at the beginning of a line and is followed by the name of
     the class of the method, the name of the method, and its arguments,
     if any.

     For example:
          @defmethod bar-class bar-method argument
          ...
          @end defmethod

     illustrates the definition for a method called 'bar-method' of the
     class 'bar-class'.  The method takes an argument.

     '@defmethod' creates an entry in the index of functions.

'@deftypemethod CLASS DATA-TYPE NAME ARGUMENTS...'
     The '@deftypemethod' command is the definition command for methods
     in object-oriented typed languages, such as C++ and Java.  It is
     similar to the '@defmethod' command with the addition of the
     DATA-TYPE parameter to specify the return type of the method.
     '@deftypemethod' creates an entry in the index of functions.

  The typed commands are affected by the '@deftypefnnewline' option
(Note: Functions in Typed Languages.).